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  1. 02 Dec, 2016 15 commits
    • John David Anglin's avatar
      parisc: Fix race in pci-dma.c · 7a1ab6a2
      John David Anglin authored 
      commit c0452fb9 upstream.

We are still troubled by occasional random segmentation faults and
memory memory corruption on SMP machines.  The causes quite a few
package builds to fail on the Debian buildd machines for parisc.  When
gcc-6 failed to build three times in a row, I looked again at the TLB
related code.  I found a couple of issues.  This is the first.

In general, we need to ensure page table updates and corresponding TLB
purges are atomic.  The attached patch fixes an instance in pci-dma.c
where the page table update was not guarded by the TLB lock.

Tested on rp3440 and c8000.  So far, no further random segmentation
faults have been observed.
Signed-off-by: default avatarJohn David Anglin  <dave.anglin@bell.net>
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7a1ab6a2
    • John David Anglin's avatar
      parisc: Fix races in parisc_setup_cache_timing() · e541fd81
      John David Anglin authored 
      commit 741dc7bf upstream.

Helge reported to me the following startup crash:

[    0.000000] Linux version 4.8.0-1-parisc64-smp (debian-kernel@lists.debian.org) (gcc version 5.4.1 20161019 (GCC) ) #1 SMP Debian 4.8.7-1 (2016-11-13)
[    0.000000] The 64-bit Kernel has started...
[    0.000000] Kernel default page size is 4 KB. Huge pages enabled with 1 MB physical and 2 MB virtual size.
[    0.000000] Determining PDC firmware type: System Map.
[    0.000000] model 9000/785/J5000
[    0.000000] Total Memory: 2048 MB
[    0.000000] Memory: 2018528K/2097152K available (9272K kernel code, 3053K rwdata, 1319K rodata, 1024K init, 840K bss, 78624K reserved, 0K cma-reserved)
[    0.000000] virtual kernel memory layout:
[    0.000000]     vmalloc : 0x0000000000008000 - 0x000000003f000000   (1007 MB)
[    0.000000]     memory  : 0x0000000040000000 - 0x00000000c0000000   (2048 MB)
[    0.000000]       .init : 0x0000000040100000 - 0x0000000040200000   (1024 kB)
[    0.000000]       .data : 0x0000000040b0e000 - 0x0000000040f533e0   (4372 kB)
[    0.000000]       .text : 0x0000000040200000 - 0x0000000040b0e000   (9272 kB)
[    0.768910] Brought up 1 CPUs
[    0.992465] NET: Registered protocol family 16
[    2.429981] Releasing cpu 1 now, hpa=fffffffffffa2000
[    2.635751] CPU(s): 2 out of 2 PA8500 (PCX-W) at 440.000000 MHz online
[    2.726692] Setting cache flush threshold to 1024 kB
[    2.729932] Not-handled unaligned insn 0x43ffff80
[    2.798114] Setting TLB flush threshold to 140 kB
[    2.928039] Unaligned handler failed, ret = -1
[    3.000419]       _______________________________
[    3.000419]      < Your System ate a SPARC! Gah! >
[    3.000419]       -------------------------------
[    3.000419]              \   ^__^
[    3.000419]                  (__)\       )\/\
[    3.000419]                   U  ||----w |
[    3.000419]                      ||     ||
[    9.340055] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.8.0-1-parisc64-smp #1 Debian 4.8.7-1
[    9.448082] task: 00000000bfd48060 task.stack: 00000000bfd50000
[    9.528040]
[   10.760029] IASQ: 0000000000000000 0000000000000000 IAOQ: 000000004025d154 000000004025d158
[   10.868052]  IIR: 43ffff80    ISR: 0000000000340000  IOR: 000001ff54150960
[   10.960029]  CPU:        1   CR30: 00000000bfd50000 CR31: 0000000011111111
[   11.052057]  ORIG_R28: 000000004021e3b4
[   11.100045]  IAOQ[0]: irq_exit+0x94/0x120
[   11.152062]  IAOQ[1]: irq_exit+0x98/0x120
[   11.208031]  RP(r2): irq_exit+0xb8/0x120
[   11.256074] Backtrace:
[   11.288067]  [<00000000402cd944>] cpu_startup_entry+0x1e4/0x598
[   11.368058]  [<0000000040109528>] smp_callin+0x2c0/0x2f0
[   11.436308]  [<00000000402b53fc>] update_curr+0x18c/0x2d0
[   11.508055]  [<00000000402b73b8>] dequeue_entity+0x2c0/0x1030
[   11.584040]  [<00000000402b3cc0>] set_next_entity+0x80/0xd30
[   11.660069]  [<00000000402c1594>] pick_next_task_fair+0x614/0x720
[   11.740085]  [<000000004020dd34>] __schedule+0x394/0xa60
[   11.808054]  [<000000004020e488>] schedule+0x88/0x118
[   11.876039]  [<0000000040283d3c>] rescuer_thread+0x4d4/0x5b0
[   11.948090]  [<000000004028fc4c>] kthread+0x1ec/0x248
[   12.016053]  [<0000000040205020>] end_fault_vector+0x20/0xc0
[   12.092239]  [<00000000402050c0>] _switch_to_ret+0x0/0xf40
[   12.164044]
[   12.184036] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.8.0-1-parisc64-smp #1 Debian 4.8.7-1
[   12.244040] Backtrace:
[   12.244040]  [<000000004021c480>] show_stack+0x68/0x80
[   12.244040]  [<00000000406f332c>] dump_stack+0xec/0x168
[   12.244040]  [<000000004021c74c>] die_if_kernel+0x25c/0x430
[   12.244040]  [<000000004022d320>] handle_unaligned+0xb48/0xb50
[   12.244040]
[   12.632066] ---[ end trace 9ca05a7215c7bbb2 ]---
[   12.692036] Kernel panic - not syncing: Attempted to kill the idle task!

We have the insn 0x43ffff80 in IIR but from IAOQ we should have:
   4025d150:   0f f3 20 df     ldd,s r19(r31),r31
   4025d154:   0f 9f 00 9c     ldw r31(ret0),ret0
   4025d158:   bf 80 20 58     cmpb,*<> r0,ret0,4025d18c <irq_exit+0xcc>

Cpu0 has just completed running parisc_setup_cache_timing:

[    2.429981] Releasing cpu 1 now, hpa=fffffffffffa2000
[    2.635751] CPU(s): 2 out of 2 PA8500 (PCX-W) at 440.000000 MHz online
[    2.726692] Setting cache flush threshold to 1024 kB
[    2.729932] Not-handled unaligned insn 0x43ffff80
[    2.798114] Setting TLB flush threshold to 140 kB
[    2.928039] Unaligned handler failed, ret = -1

From the backtrace, cpu1 is in smp_callin:

void __init smp_callin(void)
{
       int slave_id = cpu_now_booting;

       smp_cpu_init(slave_id);
       preempt_disable();

       flush_cache_all_local(); /* start with known state */
       flush_tlb_all_local(NULL);

       local_irq_enable();  /* Interrupts have been off until now */

       cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

So, it has just flushed its caches and the TLB. It would seem either the
flushes in parisc_setup_cache_timing or smp_callin have corrupted kernel
memory.

The attached patch reworks parisc_setup_cache_timing to remove the races
in setting the cache and TLB flush thresholds. It also corrects the
number of bytes flushed in the TLB calculation.

The patch flushes the cache and TLB on cpu0 before starting the
secondary processors so that they are started from a known state.

Tested with a few reboots on c8000.
Signed-off-by: default avatarJohn David Anglin  <dave.anglin@bell.net>
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e541fd81
    • Arnd Bergmann's avatar
      NFSv4.x: hide array-bounds warning · 0c0ddbf7
      Arnd Bergmann authored 
      commit d55b352b upstream.

A correct bugfix introduced a harmless warning that shows up with gcc-7:

fs/nfs/callback.c: In function 'nfs_callback_up':
fs/nfs/callback.c:214:14: error: array subscript is outside array bounds [-Werror=array-bounds]

What happens here is that the 'minorversion == 0' check tells the
compiler that we assume minorversion can be something other than 0,
but when CONFIG_NFS_V4_1 is disabled that would be invalid and
result in an out-of-bounds access.

The added check for IS_ENABLED(CONFIG_NFS_V4_1) tells gcc that this
really can't happen, which makes the code slightly smaller and also
avoids the warning.

The bugfix that introduced the warning is marked for stable backports,
we want this one backported to the same releases.

Fixes: 98b0f80c ("NFSv4.x: Fix a refcount leak in nfs_callback_up_net")
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0c0ddbf7
    • John Johansen's avatar
      apparmor: fix change_hat not finding hat after policy replacement · be79d7fa
      John Johansen authored 
      commit 3d40658c upstream.

After a policy replacement, the task cred may be out of date and need
to be updated. However change_hat is using the stale profiles from
the out of date cred resulting in either: a stale profile being applied
or, incorrect failure when searching for a hat profile as it has been
migrated to the new parent profile.

Fixes: 01e2b670 (failure to find hat)
Fixes: 898127c3 (stale policy being applied)
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1000287Signed-off-by: default avatarJohn Johansen <john.johansen@canonical.com>
Signed-off-by: default avatarJames Morris <james.l.morris@oracle.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      be79d7fa
    • Johannes Berg's avatar
      cfg80211: limit scan results cache size · 8316338a
      Johannes Berg authored 
      commit 9853a55e upstream.

It's possible to make scanning consume almost arbitrary amounts
of memory, e.g. by sending beacon frames with random BSSIDs at
high rates while somebody is scanning.

Limit the number of BSS table entries we're willing to cache to
1000, limiting maximum memory usage to maybe 4-5MB, but lower
in practice - that would be the case for having both full-sized
beacon and probe response frames for each entry; this seems not
possible in practice, so a limit of 1000 entries will likely be
closer to 0.5 MB.
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8316338a
    • Chris Metcalf's avatar
      tile: avoid using clocksource_cyc2ns with absolute cycle count · 4df31626
      Chris Metcalf authored 
      commit e658a6f1 upstream.

For large values of "mult" and long uptimes, the intermediate
result of "cycles * mult" can overflow 64 bits.  For example,
the tile platform calls clocksource_cyc2ns with a 1.2 GHz clock;
we have mult = 853, and after 208.5 days, we overflow 64 bits.

Since clocksource_cyc2ns() is intended to be used for relative
cycle counts, not absolute cycle counts, performance is more
importance than accepting a wider range of cycle values.  So,
just use mult_frac() directly in tile's sched_clock().

Commit 4cecf6d4 ("sched, x86: Avoid unnecessary overflow
in sched_clock") by Salman Qazi results in essentially the same
generated code for x86 as this change does for tile.  In fact,
a follow-on change by Salman introduced mult_frac() and switched
to using it, so the C code was largely identical at that point too.

Peter Zijlstra then added mul_u64_u32_shr() and switched x86
to use it.  This is, in principle, better; by optimizing the
64x64->64 multiplies to be 32x32->64 multiplies we can potentially
save some time.  However, the compiler piplines the 64x64->64
multiplies pretty well, and the conditional branch in the generic
mul_u64_u32_shr() causes some bubbles in execution, with the
result that it's pretty much a wash.  If tilegx provided its own
implementation of mul_u64_u32_shr() without the conditional branch,
we could potentially save 3 cycles, but that seems like small gain
for a fair amount of additional build scaffolding; no other platform
currently provides a mul_u64_u32_shr() override, and tile doesn't
currently have an <asm/div64.h> header to put the override in.

Additionally, gcc currently has an optimization bug that prevents
it from recognizing the opportunity to use a 32x32->64 multiply,
and so the result would be no better than the existing mult_frac()
until such time as the compiler is fixed.

For now, just using mult_frac() seems like the right answer.
Signed-off-by: default avatarChris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4df31626
    • Andrey Grodzovsky's avatar
      scsi: mpt3sas: Fix secure erase premature termination · ffffc1ed
      Andrey Grodzovsky authored 
      commit 18f6084a upstream.

This is a work around for a bug with LSI Fusion MPT SAS2 when perfoming
secure erase. Due to the very long time the operation takes, commands
issued during the erase will time out and will trigger execution of the
abort hook. Even though the abort hook is called for the specific
command which timed out, this leads to entire device halt
(scsi_state terminated) and premature termination of the secure erase.

Set device state to busy while ATA passthrough commands are in progress.

[mkp: hand applied to 4.9/scsi-fixes, tweaked patch description]
Signed-off-by: default avatarAndrey Grodzovsky <andrey2805@gmail.com>
Acked-by: default avatarSreekanth Reddy <Sreekanth.Reddy@broadcom.com>
Cc: <linux-scsi@vger.kernel.org>
Cc: Sathya Prakash <sathya.prakash@broadcom.com>
Cc: Chaitra P B <chaitra.basappa@broadcom.com>
Cc: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
Cc: Sreekanth Reddy <Sreekanth.Reddy@broadcom.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ffffc1ed
    • Petr Vandrovec's avatar
      Fix USB CB/CBI storage devices with CONFIG_VMAP_STACK=y · ab0867dd
      Petr Vandrovec authored 
      commit 2ce9d227 upstream.

Some code (all error handling) submits CDBs that are allocated
on the stack.  This breaks with CB/CBI code that tries to create
URB directly from SCSI command buffer - which happens to be in
vmalloced memory with vmalloced kernel stacks.

Let's make copy of the command in usb_stor_CB_transport.
Signed-off-by: default avatarPetr Vandrovec <petr@vandrovec.name>
Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ab0867dd
    • Doug Brown's avatar
      USB: serial: ftdi_sio: add support for TI CC3200 LaunchPad · f3f95f17
      Doug Brown authored 
      commit 9bfef729 upstream.

This patch adds support for the TI CC3200 LaunchPad board, which uses a
custom USB vendor ID and product ID. Channel A is used for JTAG, and
channel B is used for a UART.
Signed-off-by: default avatarDoug Brown <doug@schmorgal.com>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f3f95f17
    • Paul Jakma's avatar
      USB: serial: cp210x: add ID for the Zone DPMX · 1f36db0b
      Paul Jakma authored 
      commit 2ab13292 upstream.

The BRIM Brothers Zone DPMX is a bicycle powermeter. This ID is for the USB
serial interface in its charging dock for the control pods, via which some
settings for the pods can be modified.
Signed-off-by: default avatarPaul Jakma <paul@jakma.org>
Cc: Barry Redmond <barry@brimbrothers.com>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1f36db0b
    • Peter Chen's avatar
      usb: chipidea: move the lock initialization to core file · 55d061bf
      Peter Chen authored 
      commit a5d906bb upstream.

This can fix below dump when the lock is accessed at host
mode due to it is not initialized.

[   46.119638] INFO: trying to register non-static key.
[   46.124643] the code is fine but needs lockdep annotation.
[   46.130144] turning off the locking correctness validator.
[   46.135659] CPU: 0 PID: 690 Comm: cat Not tainted 4.9.0-rc3-00079-g4b75f1d #1210
[   46.143075] Hardware name: Freescale i.MX6 SoloX (Device Tree)
[   46.148923] Backtrace:
[   46.151448] [<c010c460>] (dump_backtrace) from [<c010c658>] (show_stack+0x18/0x1c)
[   46.159038]  r7:edf52000
[   46.161412]  r6:60000193
[   46.163967]  r5:00000000
[   46.165035]  r4:c0e25c2c

[   46.169109] [<c010c640>] (show_stack) from [<c03f58a4>] (dump_stack+0xb4/0xe8)
[   46.176362] [<c03f57f0>] (dump_stack) from [<c016d690>] (register_lock_class+0x4fc/0x56c)
[   46.184554]  r10:c0e25d24
[   46.187014]  r9:edf53e70
[   46.189569]  r8:c1642444
[   46.190637]  r7:ee9da024
[   46.193191]  r6:00000000
[   46.194258]  r5:00000000
[   46.196812]  r4:00000000
[   46.199185]  r3:00000001

[   46.203259] [<c016d194>] (register_lock_class) from [<c0171294>] (__lock_acquire+0x80/0x10f0)
[   46.211797]  r10:c0e25d24
[   46.214257]  r9:edf53e70
[   46.216813]  r8:ee9da024
[   46.217880]  r7:c1642444
[   46.220435]  r6:edcd1800
[   46.221502]  r5:60000193
[   46.224057]  r4:00000000

[   46.227953] [<c0171214>] (__lock_acquire) from [<c01726c0>] (lock_acquire+0x74/0x94)
[   46.235710]  r10:00000001
[   46.238169]  r9:edf53e70
[   46.240723]  r8:edf53f80
[   46.241790]  r7:00000001
[   46.244344]  r6:00000001
[   46.245412]  r5:60000193
[   46.247966]  r4:00000000

[   46.251866] [<c017264c>] (lock_acquire) from [<c096c8fc>] (_raw_spin_lock_irqsave+0x40/0x54)
[   46.260319]  r7:ee1c6a00
[   46.262691]  r6:c062a570
[   46.265247]  r5:20000113
[   46.266314]  r4:ee9da014

[   46.270393] [<c096c8bc>] (_raw_spin_lock_irqsave) from [<c062a570>] (ci_port_test_show+0x2c/0x70)
[   46.279280]  r6:eebd2000
[   46.281652]  r5:ee9da010
[   46.284207]  r4:ee9da014

[   46.286810] [<c062a544>] (ci_port_test_show) from [<c0248d04>] (seq_read+0x1ac/0x4f8)
[   46.294655]  r9:edf53e70
[   46.297028]  r8:edf53f80
[   46.299583]  r7:ee1c6a00
[   46.300650]  r6:00000001
[   46.303205]  r5:00000000
[   46.304273]  r4:eebd2000
[   46.306850] [<c0248b58>] (seq_read) from [<c039e864>] (full_proxy_read+0x54/0x6c)
[   46.314348]  r10:00000000
[   46.316808]  r9:c0a6ad30
[   46.319363]  r8:edf53f80
[   46.320430]  r7:00020000
[   46.322986]  r6:b6de3000
[   46.324053]  r5:ee1c6a00
[   46.326607]  r4:c0248b58

[   46.330505] [<c039e810>] (full_proxy_read) from [<c021ec98>] (__vfs_read+0x34/0x118)
[   46.338262]  r9:edf52000
[   46.340635]  r8:c0107fc4
[   46.343190]  r7:00020000
[   46.344257]  r6:edf53f80
[   46.346812]  r5:c039e810
[   46.347879]  r4:ee1c6a00
[   46.350447] [<c021ec64>] (__vfs_read) from [<c021fbd0>] (vfs_read+0x8c/0x11c)
[   46.357597]  r9:edf52000
[   46.359969]  r8:c0107fc4
[   46.362524]  r7:edf53f80
[   46.363592]  r6:b6de3000
[   46.366147]  r5:ee1c6a00
[   46.367214]  r4:00020000
[   46.369782] [<c021fb44>] (vfs_read) from [<c0220a4c>] (SyS_read+0x4c/0xa8)
[   46.376672]  r8:c0107fc4
[   46.379045]  r7:00020000
[   46.381600]  r6:b6de3000
[   46.382667]  r5:ee1c6a00
[   46.385222]  r4:ee1c6a00

[   46.387817] [<c0220a00>] (SyS_read) from [<c0107e20>] (ret_fast_syscall+0x0/0x1c)
[   46.395314]  r7:00000003
[   46.397687]  r6:b6de3000
[   46.400243]  r5:00020000
[   46.401310]  r4:00020000

Fixes: 26c696c6 ("USB: Chipidea: rename struct ci13xxx variables from udc to ci")
Signed-off-by: default avatarPeter Chen <peter.chen@nxp.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      55d061bf
    • Radim Krčmář's avatar
      KVM: x86: check for pic and ioapic presence before use · 341f9730
      Radim Krčmář authored 
      commit df492896 upstream.

Split irqchip allows pic and ioapic routes to be used without them being
created, which results in NULL access.  Check for NULL and avoid it.
(The setup is too racy for a nicer solutions.)

Found by syzkaller:

  general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
  Dumping ftrace buffer:
     (ftrace buffer empty)
  Modules linked in:
  CPU: 3 PID: 11923 Comm: kworker/3:2 Not tainted 4.9.0-rc5+ #27
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Workqueue: events irqfd_inject
  task: ffff88006a06c7c0 task.stack: ffff880068638000
  RIP: 0010:[...]  [...] __lock_acquire+0xb35/0x3380 kernel/locking/lockdep.c:3221
  RSP: 0000:ffff88006863ea20  EFLAGS: 00010006
  RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
  RDX: 0000000000000039 RSI: 0000000000000000 RDI: 1ffff1000d0c7d9e
  RBP: ffff88006863ef58 R08: 0000000000000001 R09: 0000000000000000
  R10: 00000000000001c8 R11: 0000000000000000 R12: ffff88006a06c7c0
  R13: 0000000000000001 R14: ffffffff8baab1a0 R15: 0000000000000001
  FS:  0000000000000000(0000) GS:ffff88006d100000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000004abdd0 CR3: 000000003e2f2000 CR4: 00000000000026e0
  Stack:
   ffffffff894d0098 1ffff1000d0c7d56 ffff88006863ecd0 dffffc0000000000
   ffff88006a06c7c0 0000000000000000 ffff88006863ecf8 0000000000000082
   0000000000000000 ffffffff815dd7c1 ffffffff00000000 ffffffff00000000
  Call Trace:
   [...] lock_acquire+0x2a2/0x790 kernel/locking/lockdep.c:3746
   [...] __raw_spin_lock include/linux/spinlock_api_smp.h:144
   [...] _raw_spin_lock+0x38/0x50 kernel/locking/spinlock.c:151
   [...] spin_lock include/linux/spinlock.h:302
   [...] kvm_ioapic_set_irq+0x4c/0x100 arch/x86/kvm/ioapic.c:379
   [...] kvm_set_ioapic_irq+0x8f/0xc0 arch/x86/kvm/irq_comm.c:52
   [...] kvm_set_irq+0x239/0x640 arch/x86/kvm/../../../virt/kvm/irqchip.c:101
   [...] irqfd_inject+0xb4/0x150 arch/x86/kvm/../../../virt/kvm/eventfd.c:60
   [...] process_one_work+0xb40/0x1ba0 kernel/workqueue.c:2096
   [...] worker_thread+0x214/0x18a0 kernel/workqueue.c:2230
   [...] kthread+0x328/0x3e0 kernel/kthread.c:209
   [...] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433
Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
Fixes: 49df6397 ("KVM: x86: Split the APIC from the rest of IRQCHIP.")
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      341f9730
    • Radim Krčmář's avatar
      KVM: x86: drop error recovery in em_jmp_far and em_ret_far · b7f9404d
      Radim Krčmář authored 
      commit 2117d539 upstream.

em_jmp_far and em_ret_far assumed that setting IP can only fail in 64
bit mode, but syzkaller proved otherwise (and SDM agrees).
Code segment was restored upon failure, but it was left uninitialized
outside of long mode, which could lead to a leak of host kernel stack.
We could have fixed that by always saving and restoring the CS, but we
take a simpler approach and just break any guest that manages to fail
as the error recovery is error-prone and modern CPUs don't need emulator
for this.

Found by syzkaller:

  WARNING: CPU: 2 PID: 3668 at arch/x86/kvm/emulate.c:2217 em_ret_far+0x428/0x480
  Kernel panic - not syncing: panic_on_warn set ...

  CPU: 2 PID: 3668 Comm: syz-executor Not tainted 4.9.0-rc4+ #49
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
   [...]
  Call Trace:
   [...] __dump_stack lib/dump_stack.c:15
   [...] dump_stack+0xb3/0x118 lib/dump_stack.c:51
   [...] panic+0x1b7/0x3a3 kernel/panic.c:179
   [...] __warn+0x1c4/0x1e0 kernel/panic.c:542
   [...] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
   [...] em_ret_far+0x428/0x480 arch/x86/kvm/emulate.c:2217
   [...] em_ret_far_imm+0x17/0x70 arch/x86/kvm/emulate.c:2227
   [...] x86_emulate_insn+0x87a/0x3730 arch/x86/kvm/emulate.c:5294
   [...] x86_emulate_instruction+0x520/0x1ba0 arch/x86/kvm/x86.c:5545
   [...] emulate_instruction arch/x86/include/asm/kvm_host.h:1116
   [...] complete_emulated_io arch/x86/kvm/x86.c:6870
   [...] complete_emulated_mmio+0x4e9/0x710 arch/x86/kvm/x86.c:6934
   [...] kvm_arch_vcpu_ioctl_run+0x3b7a/0x5a90 arch/x86/kvm/x86.c:6978
   [...] kvm_vcpu_ioctl+0x61e/0xdd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2557
   [...] vfs_ioctl fs/ioctl.c:43
   [...] do_vfs_ioctl+0x18c/0x1040 fs/ioctl.c:679
   [...] SYSC_ioctl fs/ioctl.c:694
   [...] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
   [...] entry_SYSCALL_64_fastpath+0x1f/0xc2
Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
Fixes: d1442d85 ("KVM: x86: Handle errors when RIP is set during far jumps")
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b7f9404d
    • Ashok Raj's avatar
      iommu/vt-d: Fix IOMMU lookup for SR-IOV Virtual Functions · c091bbdd
      Ashok Raj authored 
      commit 1c387188 upstream.

The VT-d specification (§8.3.3) says:
    ‘Virtual Functions’ of a ‘Physical Function’ are under the scope
    of the same remapping unit as the ‘Physical Function’.

The BIOS is not required to list all the possible VFs in the scope
tables, and arguably *shouldn't* make any attempt to do so, since there
could be a huge number of them.

This has been broken basically for ever — the VF is never going to match
against a specific unit's scope, so it ends up being assigned to the
INCLUDE_ALL IOMMU. Which was always actually correct by coincidence, but
now we're looking at Root-Complex integrated devices with SR-IOV support
it's going to start being wrong.

Fix it to simply use pci_physfn() before doing the lookup for PCI devices.
Signed-off-by: default avatarSainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c091bbdd
    • David Woodhouse's avatar
      iommu/vt-d: Fix PASID table allocation · d88a1bd0
      David Woodhouse authored 
      commit 91017044 upstream.

Somehow I ended up with an off-by-three error in calculating the size of
the PASID and PASID State tables, which triggers allocations failures as
those tables unfortunately have to be physically contiguous.

In fact, even the *correct* maximum size of 8MiB is problematic and is
wont to lead to allocation failures. Since I have extracted a promise
that this *will* be fixed in hardware, I'm happy to limit it on the
current hardware to a maximum of 0x20000 PASIDs, which gives us 1MiB
tables — still not ideal, but better than before.

Reported by Mika Kuoppala <mika.kuoppala@linux.intel.com> and also by
Xunlei Pang <xlpang@redhat.com> who submitted a simpler patch to fix
only the allocation (and not the free) to the "correct" limit... which
was still problematic.
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d88a1bd0
  3. 26 Nov, 2016 25 commits
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